Ted,
I'm going to make a kinda generic answer here with some of the info taken from a thread where we discussed the different types of trainers and training classes. These are some signs that would make me think twice about a breeder if I saw them on their website:
The breeders register the dogs with one of the "off" registering bodies - if the dogs aren't registered with the AKC ( for a U.S. purchase ) or the SV or KNPV or FCI in Europe, look elsewhere. ( this doesn't hold true so much for Mals, where the papers do matter as much to the handlers - I have a Mal cross myself... )
If the breeders are listing titles on the breeding dogs that are generally considered bogus. If you're looking for a working line dog and the breeder has the CGC, TT, etc listed as titles, this should raise alarm bells. Accept valid titles, or ask why the dogs in use are non-titled ( there are good reasons for breeding non-titled dogs, but the "I'm a small breeder and I've never titled a dog" is a reason to look elsewhere).
Find out if the breeder is or was a competitor or worked dogs for a career - they'll have a better idea about what it takes for a dog to succeed in whatever venue of competition that they're breeding for. This worth checking into when you're looking for a working dog. They are several retired serious competitors, Police K9 Officers, etc. that have serious breeding programs and have a wealth of knowledge, but you won't know the difference between them and a backyard breeder unless you ask.
Check the breeder's affiliations. This is just me, but when I see that GSDCA posted across their website, I know that the odds of getting a good working dog just dropped dramatically. If you want a working dog, the breeder should be at least semi-affiliated with working dog organizations - that's just common sense. A breeders link area gives you a very good idea about what's important to them, make sure you check it out when evaluating a breeder.
I'd be worried when the breeders simply buy titled dogs from Europe and *never* trial them or work them in seminars, etc, once they get here. They'll have a better idea of the dogs true worth if they spend some time on the field with them. Ask to have the breeders work the dogs in question if possible ( not always possible for a dam after a litter, I know )
I'm very suspicious of breeders that need to post pictures of all the celebrities that have bought dogs from them - this is a sign that the breeder doesn't have a clue. I'd rather see pictures of serious competitors that bought dogs from them.
For the site that have video's of their dogs being worked - view them with a critical eye. Are the dogs working in the appropriate drive that the breeder is describing? Is the helper work good - I mean are they actually testing the dog or just giving the dog a cookie bite?
For me, if their video's suck, I always ask myself - is that the best that they can do? And if they don't care how their dogs look in something as important as a video that everyone can view, what's their attitude towards the rest of their breeding and sales?
The above are just my opinion, but I think that they're decent guildlines to weeding out the breeders that won't fit the bill in your case.